Mammalian Heart Structure

Lesson Overview

Duration: 60 minutes
Class Size: 30 students
Subject: Science (Biology)
Year Group: Year 10
Specification: Edexcel GCSE Biology (9-1)
Topic: Structure and function of the mammalian heart

---

National Curriculum Links

• Biology Programme of Study KS4:
  • B2.4.1 describe the structure of the heart and the function of its components
  • B2.1.1 understand cell and organ structure relating to function
  • B2.5.2 use models or dissections to explore the anatomy of organisms
  • Working Scientifically: planning and conducting scientific enquiries with attention to safety and data interpretation

---

Learning Objectives

By the end of this lesson, students will be able to:

1. Identify and label the major anatomical structures of the mammalian heart including atria, ventricles, valves, arteries, and veins.
2. Explain the function of each part of the heart and how it contributes to blood circulation.
3. Demonstrate understanding through a practical dissection of a mammalian heart (e.g. lamb heart), observing and describing internal and external features.
4. Apply knowledge of heart structure and function to explain circulatory system efficiency and adaptations in mammals.
5. Evaluate dissection findings and link anatomical structure to function using scientific terminology.

---

Resources

• Preserved mammalian hearts (lamb or ox) – one per pair of students
• Dissection kits: scalpels, scissors, forceps, dissecting trays
• Safety goggles and gloves (latex or nitrile) for all students
• Heart structure diagrams and annotated handouts
• Whiteboard and markers
• Projector for digital heart anatomy animation/video
• Worksheets for lab observations and assessment questions
• First aid kit on hand

---

Safety Considerations

• Enforce strict use of PPE: goggles and gloves at all times during dissection
• Carefully instruct correct handling and use of sharp instruments
• Ensure hand washing stations are accessible post-dissection
• Use of preserved animal tissue must comply with school regulations and health guidelines
• Adequate ventilation in room
• Dispose of biological materials following school biohazard protocols

---

Lesson Structure

1. Starter: Introduction & Prior Knowledge (10 minutes)

• Quick quiz: Ask students to name parts of the heart they already know and their functions (whiteboard brainstorm).
• Show brief animation of blood flow through the heart highlighting the chambers, valves, and vessels.
• Outline the learning objectives and how the dissection will help reinforce theory.

2. Teacher-led Input: Heart Anatomy (15 minutes)

• Use a large diagram on the whiteboard or projector to introduce:
  • Four chambers: left/right atria and ventricles
  • Valves: mitral, tricuspid, aortic, pulmonary
  • Major blood vessels: vena cava, pulmonary artery/vein, aorta
• Explain functions of each part clearly with linked physiology:
  • How valves prevent backflow
  • Thickness differences in ventricles reflecting pumping strength
  • Role of arteries and veins in carrying oxygenated vs deoxygenated blood
• Introduce terms: myocardium, septum, coronary arteries

3. Practical Activity: Heart Dissection (25 minutes)

• Arrange students in pairs with prepared dissection kits and a heart specimen each.
• Demonstrate initial external observations: identify major vessels and heart shape.
• Guide students to carefully dissect the heart to reveal internal structures: chambers and valves.
• Students complete labelled drawings/notes in workbooks.
• Teacher circulates to support and question students to deepen understanding.

4. Plenary: Reflection and Assessment (10 minutes)

• Group discussion: What did the dissection reveal about heart structure and function? Any surprises?
• Quick formative quiz (written or verbal) covering:
  • Naming heart parts correctly
  • Explaining why ventricles have different wall thicknesses
  • Role of valves in circulation
• Collect completed dissection worksheets for assessment.

---

Differentiation Strategies

• Support: Provide labelled diagrams and step-by-step dissection instructions for lower ability learners.
• Challenge: Ask higher ability students to compare mammalian heart features with those of fish or amphibians briefly.
• Offer extension questions on circulatory system diseases related to valve malfunctions or heart structure.

---

Assessment Ideas

• Formative: Observation of group discussion contributions and dissection technique
• Summative:
  • Completed worksheet with labelling and written answers
  • Short test question: “Explain how the structure of the left ventricle relates to its function.”
  • Peer assessment slide: students swap annotated drawings and offer constructive feedback

---

Cross-Curricular Links

• Mathematics: Measurement skills during the dissection (e.g., size comparison, thickness measurement)
• English: Scientific writing in observation notes and explanations

---

Extension/Homework

• Research task: Investigate one cardiovascular disease related to heart structure (e.g., valve stenosis) and prepare a one-page report for next lesson.
• Video assignment: Watch a documentary extract or online resource about heart transplants and prepare questions for a follow-up discussion.

---

This lesson plan provides an immersive, hands-on learning experience fully aligned with the Edexcel GCSE Biology specification and UK National Curriculum standards, utilizing practical enquiry to deepen anatomical understanding in an engaging way.